bbrown
WKR
I run the kestrel with BA Q-core SL and either a EE Prodigy 40 or Marmot Pinnacle bag. I would not say there is a ton of room in the foot box but enough for me with out really compressing the bag. The only time I had a problem was a less than ideal campsite with just enough slope that I kept sliding to the bottom and my feet did get a bit chilly that night I am assuming because the bag was overly compressed. I had the ptarmigan before the Kestrel and it is basically the same size.
For reference I am 5'10" and my feet are size 10
For reference I am 5'10" and my feet are size 10